#include<iostream>
#include<algorithm>
using namespace std;
int n, d;
int p[100010];
int ans = 0;
int main() {
    scanf("%d %d", &n, &d);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &p[i]);
    }
    sort(p + 1, p + 1 + n);
    int now = 0;
    for (int i = 1; i <= n-2; i++) {
      
         now = i + 2;
        if (p[now] - p[i] <= d) {
            ans++;
         
        }
    }
    
   
    printf("%d", ans);
    return 0;
}